Furnace-feeding device.



No. 64u97. I Patented 1an. ls, |900.

R. M. CAMPBELL & A. H. SCHOFIELD.

FUHNACE FEEDING DEVICE. l

(Application led May 10. 1899.) (N0 Modell) 2 Sheets-Sheet i.

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y Pateteu 1an. 16, |900. n. M. CAMPBELL & A. H. scHoFlELn.

FUBNACE FEEDING DEVICE.

(Application led Muy 10, 1889.)

2 Sheets-Sheet 2.

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. W/T/VESSES ilNrrEE STATES PATENT OFFICE.

ROBERT M. CAMPBELL AND ALBERT H. SCHOFIELD, OF PORT I'IURON, MICHIGAN.

SPECIFICATION forming part of Letters Patent No. 641,497, dated January 16, 1900.

Application tiled May 10, 1899. Serial No. 716 ,248. (Nomodel.)

T0 all whom t may concern:

Be it known that we, ROBERT M. CAMPBELL and ALBERT H. ScnoEIELD, of Port Huron, in the county of St. Clair and State of Michigan, have invented a new and Improved Furnace-Feeding Device, of which the-following is a full, clear, and exact description.

Our invention is a device for use in feeding comminuted or crushed fuel to a boiler-furnace whereby the fuel is heated by hot gases drawn from the fines which carry said gases away from lthe furnace.

The invention comprises the novel features of construction hereinafter1 described and claimed.

Reference is to be had to the accompanyingv drawings, forming a part of this specication,

in which similar characters of reference indicate corresponding parts in all the figures.

Figure 1 is a longitudinal sectional elevation of a boiler and its setting, showing our device applied thereto. Fig. 2 is a sectional plan view taken upon the line 2 2 of Fig. 3. Fig. 3 is a sectional elevation taken upon the line 3 3 of Fig. l. Fig. 4 is an end elevation of the hopper by which the fuel is supplied, showing the mechanism for automatically and periodically operating the dampers; and Fig. 5 is a detail section taken upon the line 5 5 of Fig. 1.

Our device is intended particularly for use in connection with crushed or comminuted fuel; and its object is to secure a mechanism which shall introduce this fuel to the fire more advantageously than heretofore done and which shall also heat the fuel before introduction to the lire by mixing it with hot gases drawn from the uptake or discharge iiues leading from the boiler, which besides heating the fuel before introduction insures that the gases shall be perfectly consumed instead of being discharged imperfectly consumed into the chimney. The boiler B may in its principal points of construction be similar to any ordinary boiler and is set in the usual masonry A.

Ve have herein shown in connection with the boiler heaters I, located one at each side of the furnace beneath the boiler and shaped asa comparatively thin box, which is connected at each end of its upper side, by means of pipes I' and l2, respectively, with the front and rear end of the boiler. The water-supply for the boiler is passed through these heaters, being introduced through the pipes I3, which enter the heaters at their'lower edge. The grate F' is located a short distance beneath the heaters and beneath the openings e', through which the fuel is introduced to the furnace. These fuel-feeding openings are placed immediately beneath the lower edge of the heaters I.

' Fresh air for combustion purposes is passed through fines C, constructed in the boiler-setting, whereby the air is heated and is conducted from said fines to draft-openings C', communicating with the space beneath the grate F. These flues may be provided with dampers, by which the admission of air may be regulated. The gases after leaving the boiler pass upward into a smoke-stack D, which is provided with a damper cl, by means of which the flow of gases in the stack may be controlled. An arm d4 is secured to the axis of this damper outside the stack, by means of which arm the damper may be adjusted, as hereinafter described.

The fuel is introduced by any convenient means toa hopper G, which is herein shown located, as a matter of convenience, above the boiler and close to the stack. This hopper is provided with two or more rollers G', located in its lower portion and provided on their shafts at one end of the hopper with gearwheels g', meshing with each other, so tha't the rollers will turn together. .Power is applied to these rollers through a gear-wheel g, which is placed upon a shaft havin ga sprocketwheel, over which passes a belt or sprocketchain g2. The manner of applying power to the rollers may vary according to the circumstances. The rollers and the hopper are placed immediately above a pipe D, which is connected at one end with the smoke-stack D and is provided also with a damper d', by which the said pipe may be closed, thus preventing withdrawal of gases from the smoke-stack into said pipe. This damper is provided with an external crank-arm d3, which is connected, by means of a link d2, with the arm d4 upon the damper d in the smoke-stack. It is evident that these two dampers may be connected with each other directly by a link IOO which lies within the smoke-stack and the pipe D. The pipe D is connected with the discharge from the rollers G', so that the fuel which passes between the rollersis discharged into said pipe. The rollers are set so as to crush the fuel uniformly to whatever size is desired. This size is preferably quite small, so that the fuel may be carried by an air-blast to the furnace and deposited upon the fire.

At the end of the pipe D opposite its connection with the smoke-stack is placed acas-` ing E, within which is a fan f, which is rotated by means of an external pulley H, secured to its shaft and upon which a belt H is placed, said belt leading to any source of power. This fan-casing has two discharges connecting with pipes or fines E', which lead outwardly and then down upon opposite sides of the boiler through flues constructed in the boiler-setting. Each flue as it descends near to the grate is widened, so as to be substantially of a width equal to the depth of the furnace, and each iue communicates with the furnace by means of the openings c, which are comparatively small and through which the fuel is discharged into the furnace. Each iue may be provided, if desired, with a damper c, by means of which its connection with the furnace may be controlled, suc-h dampers being automatic, opening inward by the pressure of the draft and closing when the draft ceases.

Upon one end of the hopper G-the end next to thestack-as herein shown, is placed a device for automatically controlling the dampers d and d'. This device consists of a pinion g3, which is secured to the end of one of the rollers G', and a gear-Wheel K, which is journaled upon the end of the hopper and meshes with the pinion g3. The gear-wheel K has a crank-pin It projecting therefrom and engaging a lever L, said lever being pivoted at one end to the hopper G and being connected at its other end by means of a link L' with a crank-arm d5, secured upon the shaft of the damper d', by which mechanism the dampers CZ and d are alternately opened and closed, so that the draft passes at one time straight up the stack or chimney D, and at another time the damper d closes the chimney-opening, and the draft then passes into the pipe D', owing to the suction of the fan f. This draft carries with it the finely-comminuted fuel and conveys said fuel through the iiues E into the furnace. It will be noticed that the dampers d and d are so placed that when one is open the other is closed.

To more thoroughly control and distribute the fuel, deiiector-plates M are placed .in the upper part of the Iiues E' and may be adjusted to any position by means of outside handles m, so as to throw the fuel toward either the front or rear.

The mechanism described results in periodically drawing hot gases from the flues, leading the gases away from the boiler,and discharging them back into the furnace, carrying with them the finely-comminuted fuel,

which is heated thereby before being` introduced into the furnace. When the damper d is closed, the gases pass directly up the chimney, and there being no draft through the pipe D there is no feeding of fuel to the furnace. This condition will, however, last but a comparatively small portion of the time, as there will be more or less draft past the damper d', excepting for the short time when itv is completely closed. The result of this manner of feeding the furnace is that the gases are completely burned and the maxi- "mum combustion efficiency of the fuel is secured, due in part to its heating before being introduced into the furnace. The fuel being finely divided before being introduced into the furnace is quickly and thoroughly consumed. It is also possible by this means to use fuel of greatly inferior1 quality than where fuel is used in the ordinary manner by shovA eling upon thelgrate.

Having thus fully described our invention, we claim as new and desire to secure by Letters Patentl. A furnace-feeding mechanism, compris ing a fan having suction connection with the iue carrying the exhaustgases from the furnace, a fuel-supply discharging into the said connection, dampers in the flue leading from the furnace and in the connection from said flue to the fan, connections between said dampers, whereby they are held in opposite positions, and means for automatically and periodically shifting the dampers, substam tially as described.

2. A furnace-feeding mechanism,- comprising a fan having suction connection with the flue carrying the exhaust-gases from the furnace, a fuel crushingand feeding device discharging into said connection, dampers in the flues leading from the furnace and in the connection from said flue to the fan, connections between said dampers, whereby they are held in opposite positions, means for automatically and periodically shifting the dampers, and a flue leading from the fan-discharge to the furnace and discharging therein above the grates, substantially as described.

3. A furnace-feeding mechanism, comprising a fan having suction connection with the' flue carrying the exhaust-gases from the furnace, fuel-crushing rolls and means for turning them, connections between the discharge from said rolls and the fan-suction, fiues leading from the fan-discharge to the dues above the grates, dampers inthe iiue leading from the furnace and in the connection from said flue to the fan, connections between said dampers, holding them in opposite position, a crank geared to turn with one of the rolls, a lever vibrated by engaging with said crank, and-connections from said lever to the dampers, whereby they are periodically opened and shut, substantially as described.

4. A furnace-feeding device for use with a comminuted fuel, comprising a draft connecrig iion or flue leading from the flue carrying the exhaust-gases from the furnace back to the furnace above the grate, a fuel-feeding mechanism discharging into said draft connection, adjustable deiecting or guide plates in the flue between the point of receiving the fuel and the furnace, a draft-forcing mechanism connected with said draft connection, substantially as described.

5. A furnace-feeding device for use with comminuted fuel, comprising a forcing mechanism for hot gas, a fuel-feed discharging into the hot-gas supply, a iue for conducting the hot gas and fuel to the furnace, said ue expanding in one direction to substantially the Width of the furnace and discharging into the furnace through numerous openings in the Walls and adjustable guide or defiector plates within said flue and between the fuel-feed and the furnace, substantially as described.

ROBERT M. CAMPBELL. .ALBERTv H. SCHOFIELDa Witnesses:

JOHN G. COBB, WLLIAM THOMPSON. 

